In-vehicle navigation devices have been known, which acquire map information or a travel route via communication and guide a vehicle based on the acquired map information or the acquired travel route (see, for example, Patent Document 1). The navigation device disclosed in Patent Document 1 judges with a communication status recognizer of an in-vehicle terminal whether information transmission with a server unit can be conducted. When it is judged that no information transmission can be conducted, current position information, destination information and setting information acquired by the terminal are stored in an embedded memory for a waiting status. Communication condition is checked at a predetermined time interval. When it is judged that information transmission can be conducted, a terminal communicating section is controlled by a terminal system controller to send the information stored in the embedded memory to the server unit. The server sets a travel route based on the information and sends the travel route to the terminal. The terminal, which is now in good communication with the server unit and has received the travel route, guides the vehicle based on the received travel route.
[Patent Document 1] Japanese Laid-Open Patent Publication No. 2003-302242 (left column of page 6 to left column of page 11).